Prostaglandins play a major role in the inflammation process and the inhibition of prostaglandin production, especially production of PGG2, PGH2 and PGE2 has been a common target of antiinflammatory drug discovery. However, common non-steroidal antiinflammatory drugs (NSAIDs) that are active in reducing the prostaglandin-induced pain and swelling associated with the inflammation process are also active in affecting other prostaglandin-regulated processes not associated with the inflammation process. Thus, use of high doses of most common NSAIDs can produce severe side effects, including life threatening ulcers, that limit their therapeutic potential. An alternative to NSAIDs is the use of corticosteroids, which have even more drastic side effects, especially when long term therapy is involved.
Previous NSAIDs have been found to prevent the production of prostaglandins by inhibiting enzymes in the human arachidonic acid/prostaglandin pathway, including the enzyme cyclooxygenase (COX). The recent discovery of an inducible enzyme associated with inflammation (named “cyclooxygenase-2 (COX-2)” or “prostaglandin G/H synthase II”) provides a viable target of inhibition which more effectively reduces inflammation and produces fewer and less drastic side effects.
Description of the some benzopyran compounds useful for treating inflammatory conditions is provided in U.S. Pat. No.6,034,256. U.S. Pat. No.6,077,850 provides further description of benzopyran compounds useful in treating inflammatory conditions. Some further benzopyran compounds useful for treating inflammatory conditions are described in U.S. Pat. No. 6,271,253.